CMUT medical devices, methods of manufacture, systems, and related methods

Abstract

Capacitive micromachined ultrasound transducer (CMUT) devices, methods of manufacture, and systems and methods of use. The CMUT has a substrate, a peripheral wall defining a boundary of a cavity, and a membrane bonded to the peripheral wall. The pillars protruding from the substrate are surrounded by the peripheral wall. The struts contact but are not bonded to the membrane, thereby forming a cavity that resonates at a certain acoustic frequency. The CMUT is placed into the patient's vasculature in a stent, catheter, or other miniature device. The CMUT is responsive to acoustic frequencies emitted from a device external to the body, thereby serving as a sensor for sensing various characteristics of the CMUT surroundings internal to the body.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Provisional Patent Application No. 63 / 342,527, filed on May 16, 2022, entitled “CMUT DEVICE AND FABRICATION METHOD,” and U.S. Provisional Patent Application No. 63 / 342,812, filed on May 17, 2022, entitled “MEDICAL DEVICES, SYSTEMS AND RELATED METHODS,” both of which are incorporated herein by reference in their entirety. Background Art

[0003] The present invention generally relates to medical devices including sensors and electronics. In one non-limiting example, such a medical device may include an intraluminal device, such as a guidewire and a catheter, that includes various sensors for imaging and / or measuring one or more physiological parameters. In other non-limiting examples, a medical device may include an implantable sensor to provide imaging, monitoring, or measuring physiological parameters.

[0004] Among these medical devices, capacitive micromachined ultrasonic transducer (CMUT) is a relatively new technology in the field of transducers. In many applications, CMUT can be used to generate and / or receive ultrasonic waves. Due to its small size, CMUT has unique advantages in medical devices that need to provide high-precision and small sensors. However, the manufacture of such devices can be very challenging when considering performance, yield, reliability, cost, etc.

[0005] There continues to be a need for improved medical devices that can effectively integrate sensors and help provide data in a more efficient manner, and / or provide data that was previously not available in a practical manner.

[0006] The subject matter claimed herein is not limited to embodiments that solve any disadvantages or operate only in environments such as described above. Rather, this background is provided merely to illustrate one exemplary technology area in which some embodiments described herein may be practiced. Summary of the invention

[0007] At least one embodiment disclosed herein includes a capacitive micromachined ultrasonic transducer (CMUT) device including a substrate (which may include a CMOS (complementary metal oxide silicon) wafer), and one or more peripheral walls protruding from the substrate. The one or more peripheral walls define the outer boundary of the cavity. In addition, a silicon-on-insulator (SOI) wafer with a top highly doped silicon layer can be bonded to the one or more peripheral walls so that the cavity is located between the SOI and the substrate. After removing the processing wafer from the SOI wafer, a membrane located on one side of the cavity can be formed.

[0008] The CMUT may further include one or more pillars protruding from the substrate. The one or more pillars may be surrounded by one or more peripheral walls. The width of at least a portion of the one or more pillars is less than 10 microns. In addition, one or more inner walls may protrude from the substrate. The one or more inner walls may be surrounded by one or more peripheral walls.

[0009] In addition, at least one embodiment may include a capacitive micromachined ultrasonic transducer (CMUT) device. The device includes: a substrate; one or more peripheral walls protruding from the substrate, the one or more peripheral walls defining an outer boundary of a cavity; and a membrane bonded to the one or more peripheral walls, the cavity being located between the membrane and the substrate. The device also includes one or more pillars protruding from the substrate, the one or more pillars being surrounded by the one or more peripheral walls, wherein at least a portion of the one or more pillars has a width of less than 10 microns. The device also has one or more inner walls protruding from the substrate, the one or more inner walls being surrounded by the one or more peripheral walls.

[0010] Another embodiment of the present disclosure relates to a method for constructing a capacitive micromachined ultrasonic transducer (CMUT). The method includes providing one or more peripheral walls on a substrate, the one or more peripheral walls defining the outer boundary of the cavity, wherein the width of the one or more peripheral walls is at least 8 microns. The method continues to provide one or more pillars on the substrate, the one or more pillars are surrounded by the one or more peripheral walls, wherein the width of at least a portion of the one or more pillars is 1 micron to 10 microns. The method also includes providing one or more inner walls protruding from the substrate on the substrate, the one or more inner walls are surrounded by the one or more peripheral walls, wherein the width of at least a portion of the one or more inner walls is 0.5 microns to 1 micron.

[0011] Another embodiment of the present disclosure is directed to a medical device having: a body; and at least one electronic component associated with the body. The at least one electronic component includes: at least one sensor; and an ultrasonic transducer configured to receive an ultrasonic signal and thereby power the at least one sensor. The electronic component is configured to provide a responsive ultrasonic wave in response to a determination of the at least one sensor.

[0012] Another embodiment of the present disclosure is directed to a system comprising: an external device having a first ultrasound transducer; a medical device configured to be located within an anatomical structure of a patient. The medical device comprises: at least one electronic component; at least one sensor; and a second ultrasound transducer configured to receive an ultrasound signal generated by the first ultrasound transducer to power the at least one sensor. The electronic component is configured to provide a responsive ultrasound wave to the external device in response to a determination of the at least one sensor.

[0013] Other embodiments of the present disclosure are directed to a method comprising: implanting an electronic component into a patient's body adjacent to or within a tumor; powering the electronic component using ultrasound energy; and detecting a moisture content of the tumor using a sensor of the electronic component. The method also includes: providing a response signal from the electronic component to an external device based on the detected moisture content; and determining a density or density change of the tumor based on the response signal.

[0014] Other embodiments of the present disclosure are directed to a medical device, comprising: a flexible elongated member having a distal portion configured for insertion into a patient's blood vessel; and an imaging device disposed in the distal portion of the flexible elongated member. The imaging device comprises: a flexible substrate; a plurality of ultrasonic transducers disposed on the flexible substrate, each of the plurality of ultrasonic transducers comprising a complementary metal oxide silicon capacitive micromachined ultrasonic transducer (CMUT-on-CMOS) device; and a tail extending from the flexible substrate and having a plurality of connection pads.

[0015] This summary is intended to introduce some concepts in a simplified form, which are further described in the detailed description below. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to determine the scope of the claimed subject matter.

[0016] Additional features and advantages will be set forth in the following description, and in part will be apparent from the description, or may be learned by practicing the teachings herein. The features and advantages of the present invention may be realized and obtained by means of the means and combinations particularly pointed out in the appended claims. The features of the present invention will become more apparent from the following description and the appended claims, or may be learned by practicing the present invention as described below. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to describe the manner in which the above and other advantages and features can be obtained, the subject matter briefly described above will be described in more detail with reference to the specific embodiments shown in the accompanying drawings. It should be understood that these drawings depict only typical embodiments and therefore should not be considered limiting of scope. The embodiments will be described and explained in a more specific and detailed manner through the following drawings.

[0018] Figure 1 A side view of a silicon-on-insulator (SOI) wafer is shown according to an embodiment of the present disclosure.

[0019] Figure 2 A side view of a complementary metal oxide semiconductor (CMOS) wafer with a lower electrode according to an embodiment of the present disclosure is shown.

[0020] Figure 3 A side view of a CMOS wafer chamber with an oxide layer according to an embodiment of the present disclosure is shown.

[0021] Figure 4 A side view of CMOS wafer bonding according to an embodiment of the present disclosure is shown.

[0022] Figure 5 A side view of a CMUT according to an embodiment of the present disclosure is shown.

[0023] Figure 6 A top view of a CMOS wafer without a membrane is shown according to an embodiment of the present disclosure.

[0024] Figure 7 A flow chart depicting method steps for fabricating a CMUT according to an embodiment of the present disclosure is shown.

[0025] Figure 8 A catheter according to an embodiment of the present disclosure is shown.

[0026] Fig. 9 yes Figure 8 An enlarged view of a portion of the catheter depicted in FIG.

[0027] Fig.10 is along Fig. 9 A cross-sectional view along line 10-10.

[0028] Fig.11 Describes the Figure 8 An array of sensors in a catheter is shown in FIG.

[0029] Fig.12 A bracket according to an embodiment of the present disclosure is shown.

[0030] Fig.13 and Fig.14 A system according to an embodiment of the present disclosure is shown.

[0031] Fig.15 Another system according to an embodiment of the present disclosure is shown.

[0032] Fig.16 A transaortic valve is shown in accordance with an embodiment of the present disclosure.

[0033] Fig.17 Another system according to an embodiment of the disclosure is depicted.

[0034] Fig.18 A wearable patch according to an embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0035] The present disclosure provides various examples and embodiments of medical devices, systems, methods, and related components. Such devices, systems, and the like can be used for diagnosis and / or treatment of physical conditions, including detecting or determining desired parameters or characteristics. The disclosed embodiments include capacitive micromachined ultrasonic transducers (CMUTs). In some embodiments, the CMUTs can be used in medical devices. For example, the disclosed CMUTs can be used in implantable sensors, IVUS catheters, ultrasonic imaging devices, and / or other medical devices that utilize transducers. The transducers can be used to sense ultrasonic signals and / or receive ultrasonic signals.

[0036] A conventional CMUT includes a top electrode integrated into the membrane, a bottom substrate, and a cavity formed between the membrane and the substrate. When a force is applied to the conductive membrane, the membrane deforms. The deformation of the membrane causes a change in the capacitance between the membrane and the substrate. The resulting change in the electric field can be detected and / or generated by the circuit integrated in the CMUT. Conversely, applying an electrical signal to the substrate (e.g., an electrode under the membrane) causes the membrane to deform, thereby generating sound waves through the vibrating membrane. Conversely, the change in capacitance between the membrane and the substrate causes the displacement of the membrane, thereby generating ultrasonic waves.

[0037] CMUT fabrication can be performed by a number of different methods, including using sacrificial layers, cavity first, cavity last, surface micromachining, or any number of other different fabrication methods. In at least one embodiment, the disclosed CMUT is fabricated using thermal oxide growth on a SOI wafer. Figure 1 A side view of a silicon-on-insulator (SOI) wafer 100 is shown. The SOI wafer may include a handle wafer 110, a buried oxide (BOX) layer 120, and a membrane layer 130. In an example embodiment, a CMUT may be fabricated using the following parameters: 1.0um + / - 0.3um, N++ red phosphorus doping, 0.1 to 0.2Ω / cm 2 Thermal oxide growth may include, for example, at 980°C (Angstrom) to of drying.

[0038] Figure 2A side view of a complementary metal oxide semiconductor (CMOS) wafer 200 with a bottom electrode 210 on a substrate 220 is shown. The substrate may be made of silicon and may contain various circuits, such as but not limited to signal generating circuits and signal receiving circuits. In at least one embodiment, the CMOS wafer 200 is fabricated using the following parameters: UTM M8 (3um, copper) on CMOS with 1.5um oxide passivation, SiN as an exhaust barrier. Vias may be added using a copper damascene process, and the bottom electrode may also be fabricated using a copper damascene process.

[0039] Figure 3 A side view of a CMOS wafer having at least one cavity 300 formed in an oxide layer is shown. Now, the CMOS wafer may include: a peripheral wall 310 defining the cavity 300, and one or more pillars 320 located within the cavity 300. In an example embodiment, the CMOS wafer cavity may be constructed using the following parameters: CVD (Chemical Vapor Deposition) Oxide / SiN, 6-8K HDP->CMP to SiN, peripheral wall and pillar etch to stop at SiOx, and HDP Oxide.

[0040] Figure 4 A side view of CMOS wafer bonding 400 is shown. In the depicted embodiment, Figure 1 The SOI wafer 100 is bonded to a Figure 3 The CMOS wafer of at least one cavity 300 is formed. The membrane 130 is now located above the cavity. The manufacturing process may include a cleaning process (such as The bonding process may include a cleaning process), plasma activation and low temperature bonding, and annealing at 300° C. for 90 minutes after bonding. In at least one embodiment, the bonding temperature may be between about 400° C. and about 425° C. for half an hour or less. Additionally or alternatively, the bonding temperature may include a temperature less than 400° C. The low temperature bonding results in the membrane 130 being bonded to the peripheral wall 310, while in at least some embodiments, the membrane is not bonded to one or more (or all) of the pillars 320.

[0041] Figure 5A side view of the CMUT 500 after metallization and passivation is shown. The final CMUT 500 now includes one or more vias 510, one or more cells 540, and trench etching 520 to isolate the conductive film 130 from the conductive circuit integrated into the CMUT. The manufacturing process may include wafer grinding and etching processes. Etching may be used to open the contacts 550. In addition, the manufacturing process may include metal deposition for the metal grid, Ti / 1.5um Al / Ti / 1.5um Al, BOX removal, and thinning etching of the membrane 130, and trench etching. In addition, the manufacturing process may include passivation layer deposition (e.g., parameters are 0.5um SiO 2 / 0.5um SiN) and pad openings.

[0042] Figure 6 A top view 600 of a CMOS wafer without a membrane is shown. The depicted CMOS wafer includes a top view of a peripheral wall 310 that surrounds and defines a cavity 300 and one or more pillars 320 located within the cavity 300. One or more inner walls 610 protruding from the substrate 220 are also depicted. The inner walls 610 are located within the boundaries of the peripheral wall 310 and can be located between adjacent pillars 320. As shown, in at least one embodiment, the pillars 320 and the inner walls 610 help define the individual cells 540 arranged in an array within the cavity 300. Figure 5 and Figure 6 In the illustrated embodiment, the disclosed cavity exhibits a rectangular shape. In addition, in at least one embodiment, the cells 540 are in fluid communication with each other, such that a given cell 540 is not completely physically separated from its neighboring cells 540, but is fluidically open to its neighboring cells. Each cell 540 acts as a discrete transducer, each having its own discrete and addressable electrode 530.

[0043] In at least one embodiment, the acoustic performance of the CMUT can be specified by controlling the position and size of one or more pillars 320 and one or more inner walls 610. In addition, the size and shape of a given unit 540 or group of units 540 need not be the same as its adjacent units. Figure 6 The unit 540 depicted in FIG. 5 can have different shapes and sizes so as to be tuned to a variety of different specific acoustic frequencies. In addition, the relatively small size of one or more pillars 320 and one or more inner walls 610 can allow for larger electrodes 530 (such as Figure 5 ), which can improve the sensitivity and performance of the CMUT.

[0044] Thus, the disclosed CMUT may include a substrate 220 having one or more peripheral walls 310 protruding from the substrate 220. Figure 6As more clearly shown in FIG. 1 , one or more peripheral walls 310 define the outer boundaries of the cavity 300. The membrane 130 is bonded to the one or more peripheral walls 310. Figure 5 As shown, the cavity 300 is located between the membrane 130 and the substrate 220. One or more pillars 320 protrude from the substrate 220. The one or more pillars 320 are surrounded by one or more peripheral walls 310.

[0045] As used herein, the "width" of an object is relative to Figure 5 and Figure 6 The width is measured in the x-direction or z-direction as shown, so the width is a lateral measurement of the CMUT feature. In contrast, "height" or "thickness" is relative to Figure 5 The y-direction shown is measured, so the height or thickness is a vertical measurement of the CMUT feature. In particular, unless otherwise stated, the thickness or height is the vertical measurement extending from the bottom of the cavity to the top of the feature.

[0046] In at least one embodiment, the width of the peripheral wall 310 is at least 8 microns, at least 10 microns, or at least 12 microns. Additionally or alternatively, in at least one embodiment, the maximum cross-sectional width of at least a portion of one or more pillars 320 is less than 10 microns, less than 8 microns, or less than 5 microns. Furthermore, in at least one embodiment, the width (e.g., measured transversely) of the inner wall 610 is less than 10 microns, less than 8 microns, or less than 5 microns.

[0047] During the bonding process in manufacturing, the membrane 130 generally requires a minimum surface area to be physically bonded to the wall or pillar. In some embodiments, the minimum surface area may include a wall (e.g., a peripheral wall) having a width of at least 10 microns or a wall having a width of at least greater than 8 microns. Similarly, in order to physically bond to the pillar during the bonding process in manufacturing, the minimum area of ​​the pillar may include a pillar having an upper surface area of ​​at least 10 microns in size (e.g., a square pillar measuring at least 10 microns × 10 microns or a pillar having a diameter of at least 10 microns) or a pillar having an upper surface area of ​​at least 8 microns in size (e.g., a square pillar measuring at least 8 microns × 8 microns or a pillar presenting a diameter of at least 8 microns). Therefore, in some embodiments, by producing one or more peripheral walls 310 having a width of at least 8 microns, preferably at least 10 microns, the membrane is able to be physically bonded to one or more peripheral walls 310. In contrast, in some embodiments, by producing one or more pillars 320 having a cross-sectional width of less than 10 microns, preferably less than 8 microns, the membrane remains not physically bonded to one or more peripheral walls 310 during the manufacturing bonding process. Similarly, in some embodiments, by creating one or more inner walls 610 with a width less than 10 microns, preferably less than 8 microns, and more preferably less than 1 micron, the membrane remains unbonded to the one or more inner walls 610 during the manufacturing bonding process.

[0048] In at least one embodiment, the membrane 130 is not bonded to at least a portion of the one or more pillars 320. Additionally or alternatively, in at least one embodiment, the membrane 130 is not bonded to at least a portion of the one or more inner walls 610. The height of the one or more pillars 320 and / or the one or more inner walls 610 can be shorter than the height of the peripheral wall 310, for example, 2 nanometers (i.e., 1 nanometers relative to the height of the peripheral wall 310). Figure 6 ). In other embodiments, the height of one or more pillars 320 and one or more inner walls 610 may be 1 micron shorter, 0.5 micron shorter, up to 2 nanometers shorter, or any range with the above values ​​as endpoints than the height of the peripheral wall 310. Thus, the membrane 130 may be configured to bond to the peripheral wall 310 while remaining unbonded to at least a portion of the one or more pillars 320 and the one or more inner walls 610. In some embodiments, the membrane 130 is unbonded to any of the one or more pillars 320. In alternative embodiments, the membrane 130 is unbonded to a majority of the one or more pillars 320.

[0049] In at least one embodiment, by utilizing one or more pillars 320 and / or one or more inner walls 610 of relatively small size (i.e., size too small to be physically bonded to the membrane), the resulting CMUT provides a larger effective area of ​​the membrane 130. In addition, since the area requiring physical bonding is relatively small, the disclosed manufacturing embodiments allow for more reliable CMUT production. In particular, since only bonding to one or more peripheral walls 310 is required, the likelihood of manufacturing defects is lower compared to conventional bonding processes that may require bonding at one or more peripheral walls 310, one or more pillars 320, and one or more inner walls 610.

[0050] In at least one embodiment, the cavity 300 includes a negative air pressure relative to the exterior of the CMUT 500. During the manufacturing process, a vent hole can be drilled in the CMUT (e.g., through the peripheral wall 310). A vacuum can be applied to the vent hole, thereby forming a negative air pressure within the cavity 300. The resulting pressure difference can cause the membrane 130 to be pressed down onto one or more pillars 320 and / or one or more inner walls 610, causing the pillars 320 and / or inner walls 610 to support or support the membrane 130 at their respective locations (e.g., like "tent poles"). In at least one embodiment, creating cells 540 that are fluidly connected to each other also distributes the initial internal pressure in the CMUT throughout the device. For example, in a conventional CMUT, the cavity at the corner of the device can include an internal pressure of up to 10 atmospheres (atm). Such high pressure may cause the bonding of the CMUT to fail before the device can be depressurized. In contrast, the disclosed embodiments make the cells 540 fluidly open to each other so that pressure can diffuse through the device. This results in lower pressure per cell, reduces the likelihood of bond failure before the device is vented, and simplifies venting of chamber 300.

[0051] Those skilled in the art will appreciate that the use of "bonded" and "unbonded" herein refers to the state of the membrane 130 relative to the one or more peripheral walls 310, the one or more pillars 320, and the one or more inner walls 610 during the manufacturing process. In practice, after manufacturing is complete, once an electrical charge is applied to the membrane 130 and / or once negative pressure within the chamber 300 pulls the membrane downward onto the one or more pillars 320 and the one or more inner walls 610, a bond may eventually form between the membrane 130 and at least a portion of the one or more pillars 320 and the one or more inner walls 610, albeit relatively weak due to the small available surface area.

[0052] The following discussion currently relates to methods and method steps (acts) that can be performed. Although the method steps may be discussed in a specific order or shown in a flowchart in a specific order, no specific order is required unless otherwise specified or because a step depends on the completion of another step and needs to be performed in a specific order.

[0053] Figure 7 A flow chart of the steps of a method 700 for manufacturing a CMUT is depicted. The depicted method includes a step 710 of providing or forming a peripheral wall 310 on a substrate. Step 710 includes providing or forming one or more peripheral walls 310 on the substrate, the one or more peripheral walls 310 defining an outer boundary of a cavity, wherein the width of the one or more peripheral walls 310 is at least 8 microns (the definition of width is as described above with respect to Figure 6 The one or more peripheral walls may be formed by an additive or subtractive process.

[0054] The method 700 may also include a step 720 of providing or forming pillars on the substrate. Step 720 includes providing one or more pillars on the substrate, the one or more pillars 320 being laterally surrounded by one or more peripheral walls 310, wherein at least a portion of the one or more pillars 320 has a width of 1 micron to 10 microns. Additionally, the method 700 may include a step 730 of providing or forming the inner wall 610 on the substrate. Operation 730 includes providing or forming one or more walls protruding from the substrate on the substrate, the one or more walls being laterally surrounded by one or more peripheral walls, wherein at least a portion of the one or more walls has a width of 0.5 microns to 1 micron. The pillars and / or walls may be formed by additive or subtractive processes.

[0055] In further embodiments, the method 700 may further include bonding the membrane 130 to the one or more peripheral walls 310, wherein the cavity 300 is located between the membrane 130 and the substrate. The membrane 130 is bonded to the one or more peripheral walls 310 while maintaining at least a portion of the one or more pillars 320 and / or the one or more inner walls 610 bonded to the membrane 130. The method may further include degassing or venting the cavity 300 to form a negative relative pressure within the cavity and to contact the membrane with at least a portion of the pillars and / or the inner walls.

[0056] refer to Figure 8 , a catheter 800 is shown. Although the catheter is used as Figure 8 (and related Figure 9-11 ) is presented as an example associated with the catheter 800, but the components, features and embodiments described can also be applied to construct a guidewire or other elongated flexible element. The catheter 800 includes an elongated flexible body 802 (also referred to herein as an "elongated flexible member") and can be associated with a proximal device 804. In some embodiments, the proximal device 804 may include a control unit (not shown) and / or a valve device, such as described in U.S. Patent No. 11,304,659, issued on April 19, 2022, entitled “OPERATIVELY COUPLED DATAAND POWER TRANSFER DEVICE FOR MEDICAL GUIDEWIRES AND CATHETERS WITH SENSORS” or in U.S. Patent Application No. 17 / 979,629, filed on November 2, 2022, entitled “DATA AND POWER TRANSFERDEVICES FOR USE WITH MEDICAL DEVICES AND RELATED METHODS”, the disclosures of which are incorporated herein by reference in their entirety.

[0057] The catheter 800 includes one or more sensors 806. Power lines and / or data lines 808 can extend along the length of the catheter 800 to the one or more sensors 806 near the distal end 810 of the elongated body 802. As used herein, "power lines" and / or "data lines" refer to any conductive path (e.g., traces) within or on a medical device. Although multiple power lines and / or data lines can be utilized, some embodiments can be configured to transmit both power and data on a single line and / or manage sensor data signals from multiple sensors on a single line. This reduces the amount of structural wiring that must pass through the catheter 800 and more efficiently utilizes the limited space of the device while reducing the complexity of the device and the associated risk of device failure.

[0058] The proximal device 804 may include one or more ports to introduce fluids (e.g., drugs, nutrient solutions, nanoparticle colloidal solutions) into the catheter 800. The size and configuration of the body 882 or at least its distal portion may be designed to be temporarily inserted into the body and configured to, for example, provide diagnostic information or deliver an implant in the body. In one embodiment, the catheter 800 is a peripherally inserted central catheter (PICC) line, typically placed in an arm or leg to access the body's vascular system. The catheter 800 may also be a microcatheter, a central venous catheter, an IV catheter, a coronary catheter, a stent delivery catheter, a balloon catheter, an atherectomy catheter, or an IVUS catheter or other imaging catheter. The catheter 800 may be a single-lumen or multi-lumen catheter.

[0059] refer to Fig. 9 For example, the one or more sensors 806 of the catheter 800 may include, for example, a pressure sensor, a flow sensor, an imaging sensor, a component detection sensor, or a combination thereof. Additionally, while generally referred to as a "sensor" when discussing various embodiments, such "sensor" components (e.g., sensor 906) may include or be associated with a transducer or other components, and may be configured as an input device, an output device, or both.

[0060] like Fig. 9 and Fig.10 As shown, the sensors 806 are arranged circumferentially around the longitudinal axis 812 of the elongated body 802. Fig. 9 In the illustrated embodiment, the sensor 806 includes an ultrasonic transducer, which can be used for imaging (e.g., imaging of a blood vessel), for activating or releasing a therapeutic agent, or for other purposes. In one embodiment, the ultrasonic transducer can include a capacitive micromachined ultrasonic transducer (CMUT), as described above. In other embodiments, the ultrasonic transducer can include a piezoelectric transducer, such as a piezoelectric micromachined ultrasonic transducer (PMUT) or other types of ultrasonic devices.

[0061] Although in Fig. 9 and Fig.10 802, but other numbers of sensors 806 may be used, and other geometric and spatial arrangements may be utilized. Figures 1 to 3 As shown, catheter 800 may be used as a side-viewing intravenous ultrasound (IVUS) catheter for imaging blood vessels (eg, coronary vessels) to determine, for example, whether a stenosis or other condition has occurred and whether some specific intervention is required.

[0062] Brief reference Fig.11 , shows a CMUT array 830, which can be used in Fig. 9 and Fig.10 The catheter 800 shown is formed with a circumferentially arranged sensor 806, or other devices requiring a CMUT array or other sensor. The array 830 includes a flexible substrate 832 and a plurality of sensors / CMUTs 806. In one embodiment, the flexible substrate may include a polyimide material. In one embodiment, the sensor / CMUT 806 may be disposed on the flexible substrate 832, and in other embodiments, the sensor / CMUT 806 may be sandwiched between multiple layers of flexible material or otherwise surrounded by a flexible material. A flexible tail 834 may be formed integrally with the flexible substrate 832 and extend from the sensor / CMUT 806, providing a plurality of connection pads 836 for connection with other electronic devices (e.g., another flexible circuit, a ribbon cable, a single conductor, etc.). Circuits may be formed within the substrate 832 / tail 834 to connect the individual sensors / CMUTs 806 together, connect the sensor / CMUT 806 to the connection pads 836, and / or connect other electronic components associated with the CMUT array 830.

[0063] When the CMUT array 830 is applied to a catheter or other elongated body, it can be "rolled" into, for example, Fig. 9 and Fig.10 The configuration shown, and the connection pad 836 can be connected to the power line / data line (e.g., Fig.15 Although shown as including a single row of eight sensors / CMUTs 806, the CMUT array 830 may have other configurations, including a different number of sensors / CMUTs 806, multiple rows of sensors / CMUTs, staggered arrangements of sensors / CMUTs 806, etc. In addition, in some embodiments, the CMUT array 830 may include CMUTs of different specifications, including at least two CMUTs configured to operate at different frequencies.

[0064] refer to Fig.12 , shows a medical device in the form of a stent 900 according to an embodiment of the present disclosure. The stent may include a body 902 positioned within a blood vessel 904 to act as a stent or support structure at a desired location within the blood vessel 904 (e.g., within a calcified portion of a coronary artery). As will be appreciated by one of ordinary skill in the art, the stent 900 may be delivered in an initial radially contracted state by means of a catheter and then radially expanded at the location to dilate the blood vessel and open the lumen of the blood vessel to increase fluid flow. One or more electronic components 906 (e.g., sensors, systems on a chip (SOC) as described above) may be coupled to the stent 900, embedded within the stent 900, or otherwise associated with the stent 900. For example, in one embodiment, the electronic components may include an ultrasonic transducer (e.g., a CMUT chip as described above) and some other type of sensor (e.g., a pressure sensor, a flow sensor, a proximity sensor that may be separated from the CMUT chip or integrated into the CMUT chip). The electronic components 906 may be "passive" in that they are not powered or actively sensed or processed until they are actively activated by a specific external stimulus. In Fig.12 In the illustrated embodiment, there are two separate electronic components 906, one disposed near each longitudinal end of the stent 900 (eg, one at the distal end and one at the proximal end).

[0065] like Figure 6 and Figure 7 As shown, the support 900 can be used as part of a system 910, where a patch or pad 912 is placed on an outer surface 914 of a user's tissue 916. As will be discussed in detail below, the patch 912 can include one or more ultrasound transducers 918 that are configured to transmit ultrasound waves 920 (also called sound waves) into the tissue 916 and the electronic component 906 at one or more desired frequencies. In some cases, the waves 822 can be focused, such as by beamforming or using other known techniques, so that the energy from the sound waves 920 is focused at a desired location (e.g., at the location of the electronic component 906). As shown in FIG. Fig.13 As shown, ultrasonic waves may be transmitted to electronic component 906 , and energy from sound waves 920 may be used to power electronic component 906 by receiving the ultrasonic waves via an ultrasonic transducer (eg, a CMUT) associated with electronic component 906 .

[0066] When the electronic components 906 are powered, they can operate according to the desired protocol to perform the desired functions. For example, the electronic components 906 may include sensors for detecting parameters associated with the health and function of the blood vessel 904 and / or the condition or state of the stent 900. In one embodiment, the electronic components 906 may include a pressure sensor, wherein the fluid pressure can be measured to determine whether there is a significant blockage (e.g., recalcification) within the blood vessel where the stent 900 is located. For example, the pressure can be measured at each end of the stent to determine whether a pressure drop has occurred that exceeds a determined threshold. If the pressure drop exceeds an acceptable value, intervention may be required. However, determining whether intervention is required can be at least preliminarily determined without the need for additional invasive techniques. In other embodiments, the sensor can determine other parameters, such as flow rate, temperature, or other information related to vascular health diagnosis.

[0067] refer to Fig.14 , after the associated sensor has determined its designated parameters or characteristics, the electronic component 906 can transmit an ultrasonic signal (referred to herein as a "response signal 930" to distinguish it from the originally transmitted ultrasonic signal 920) to the patch 912. This can be achieved in a variety of different ways. In one example, the electronic component 906 can process the information obtained by any associated sensor and then transmit the response signal 930 back to the patch 912 through the associated transducer (e.g., CMUT).

[0068] In another embodiment, when a sensor associated with electronic component 906 detects a particular parameter state (e.g., pressure above a specified threshold), a membrane, disk, magnetic device, or some other component may change so that the transmitted sound wave 920 ( Fig.13 ) is reflected in a specified manner, forming a response wave 930. The system associated with the patch 910 recognizes the response signal to indicate that a specific parameter state has been detected. Such a system requires relatively little power, thereby enabling the size of the electronic components to be significantly reduced.

[0069] Still reference Figure 6 and Figure 7 In another embodiment, the electronic components 906 may include proximity sensors, or the system 910 may include additional processors or sensors to determine the relative position of each electronic component 906 (or a selected subset). Thus, for example, based on the relative positions of two or more electronic components 906, it may be determined whether the body 902 of the stent 902 has been sufficiently expanded (e.g., when the stent body 902 expands radially, it may also contract or shorten longitudinally, thereby changing the relative positions between the electronic components 906).

[0070] The electronic components 906 (in the above examples as well as in other embodiments) may include sensors for detecting various other parameters or characteristics associated with the health of the individual or the performance of a medical device implanted in the individual. For example, the electronic components 906 may include sensors configured to sense the presence of biological components or measure physiological parameters in a target anatomical location. Examples of biological components and physiological parameters that may be detected / measured include sugar levels, pH levels, CO 2 Level (CO 2 The sensors may be configured to sense the presence, absence or level of biological components, such as immune system-related molecules (e.g., macrophages, lymphocytes, T cells, natural killer cells, monocytes, other leukocytes, etc.), inflammatory markers (e.g., C-reactive protein, procalcitonin, amyloid A, cytokines, α-1-acid glycoprotein, ceruloplasmin, hepcidin, haptoglobin, etc.), platelets, hemoglobin, ammonia, creatinine, bilirubin, homocysteine, albumin, lactate, pyruvate, ketone bodies, ions and / or nutrient levels (e.g., glucose, urea, chloride, sodium, potassium, calcium, iron / ferritin, etc.). The sensors may be used to detect evidence of thrombosis, impedance of tissue structures (or across implanted medical devices), moisture content (e.g., to detect changes in tumor density or size), or physical dimensions of desired anatomical structures (e.g., based on the proximity of implanted electronic components).

[0071] Brief reference Fig.15 , another system 940 according to another embodiment of the present disclosure is shown. System 940 includes a support 900 having an electronic component 906 as previously described, but rather than using a patch adhered to or otherwise placed on the patient's skin, a handheld (e.g., portable) ultrasound probe 942 is employed. Probe 942 includes one or more ultrasound transducers 918 to provide energy for powering and / or communicating with the electronic component 906 in the manner described above. Probe 940 can be associated with other systems and hardware, or can be a stand-alone device.

[0072] Brief reference Fig.16 , shows a human heart 1000 undergoing a transaortic valve replacement (TAVR) procedure in which a new valve 1002 is placed within a natural diseased aortic valve. The new valve 1002 may include one or more electronic components 906 such as described above with respect to the stent embodiment. The electronic components 906 may be used as part of a system such as described above (e.g., using a patch or ultrasound probe). For example, the electronic components 906 may be used to measure pressure or flow of the new valve 1002, and / or measure proximity of the electronic components 906 to determine whether the new valve has expanded appropriately, is operating as expected, determine flow rate through the valve, or determine other parameters, characteristics, or states associated with valve and heart function.

[0073] refer to Fig.17 , another system 1100 according to another embodiment of the present disclosure is shown. System 1100 includes an electronic component 906 embedded or implanted within a tumor 1102. Electronic component 906 can be implanted within the tumor in association with another surgery, or can be implanted during a specific surgery. For example, electronic component 906 can be delivered to tumor 1102 via a needle. Although electronic component 906 is shown within the mass of tumor 1102, in some embodiments, it can be implanted in close proximity to the tumor, or can be strategically located at other locations associated with the effect of the tumor on the function of an organ or anatomical structure.

[0074] The electronic component 906 is configured to be powered by ultrasound 920 and have a sensor to determine parameters, characteristics or states related to the tumor 1102 as previously described. The probe 942 includes one or more ultrasonic transducers 918 for providing energy to power the electronic component 906 and / or communicate with the electronic component 906 in the manner described above. In other embodiments, a patch or pad as described above may be used. In one embodiment, the electronic component 906 may include a sensor configured to detect the moisture content of the tumor 1102. When the moisture content of the tumor 1102 is sensed, the information may be transmitted back to the probe 942 (or other device) as described in other embodiments above. The information provided by the electronic component 906 can be used to determine the density of the tumor 1102, thereby determining whether the tumor 1102 is reduced, increased or relatively unchanged compared to the previously determined tumor size. Therefore, the system 1100 is able to frequently monitor tumors that are being treated (e.g., by radiation, chemotherapy or other methods) to determine the effectiveness of the treatment early. In many cases, the prescribed treatment process shows effectiveness at an early stage. However, conventional monitoring methods usually require the use of expensive imaging modalities and expose patients to harmful radiation. Therefore, such imaging is usually performed after the patient has been treated for a long time (e.g., 6-8 weeks). Using the system to monitor the tumor's response to the treatment process early (e.g., within a week or two of starting treatment) enables physicians to determine early whether the treatment plan needs to be adjusted, thereby saving valuable time and resources.

[0075] Reference now Fig.18 , a schematic diagram of an example patch 912 with an ultrasonic transducer 918 is shown. The patch 912 may include a flexible membrane 1200 (e.g., polyimide or other polymer material) that can be adhered to the patient's skin. Various components may be disposed on or in the membrane 1200. For example, the patch 912 may include one or more ultrasonic transducers 918 of one or more designs. In one embodiment, the ultrasonic transducer 918 may include a capacitive transducer, such as a CMUT (capacitive micromachined ultrasonic transducer). In other embodiments, the transducer may include a piezoelectric transducer, such as a PMUT (piezoelectric micromachined ultrasonic transducer). In some embodiments, a piezoelectric ultrasonic transducer may be formed using techniques such as those described above. The ultrasonic transducer 918 may include a single transducer or an array of ultrasonic transducers. In addition, the transducer 918 may be configured to operate at multiple frequencies. Thus, for example, one frequency may be used to discharge power to the electronic component 906, while another frequency may be used to image an area of ​​interest within an individual anatomical structure.

[0076] The patch 912 may also include a processor 1202, such as an ASIC (application specific integrated circuit) or other suitable integrated circuit. A communication device 1204 (e.g., an integrated circuit) may provide wireless communication between the patch 912 and an external device (such as a personal computer, a tablet computer, a smart phone, or other such device), for example, via Bluetooth, Wi-Fi, Zigbee, or some other protocol. The external device may be used to control the patch, and / or receive information from the patch, such as the time and / or duration of activation. In some embodiments, instead of or in addition to activating or controlling the patch by an external device, the patch 912 may be provided with a dedicated button or switch to activate the patch 912 (e.g., to activate the ultrasonic transducer 918 of the patch 912). A power source 1206 may also be included, such as a battery, a capacitor, or a connector to an external power source to provide power to the various components of the patch.

[0077] Although Fig.18 The examples in the figure depict discrete components such as one or more transducers 918 and one or more processors 1202, but these components can be integrated. For example, a CMUT on CMOS (complementary metal oxide semiconductor) or a PMUT on CMOS can be used instead of a single transducer 918 and processor 1202.

[0078] Still reference Fig.18 In some embodiments, a magnetic field generator 1208 (e.g., an electromagnet) can be used to assist in focusing, steering, or otherwise manipulating ultrasound waves (transmitted waves, response waves, or both). In some cases, a magnetic field can be used to affect a disk, membrane, or other structure that affects the backscattered response waves.

[0079] Various embodiments of the present invention have been provided by way of example. However, other embodiments and configurations are also conceivable. For example, an electronic component (e.g., 906) may be associated with a left atrial appendage implant to help monitor problems associated with AFIB, such as pressure or potential thrombosis. In other embodiments, the electronic component may be implanted in an organ (e.g., the heart) directly or in combination with some other medical device to monitor desired parameters, such as elasticity, density, etc. In other embodiments, the electronic component may be implanted to monitor or detect transplant rejection, whether cell-mediated or antibody-mediated. In other embodiments, the electronic component may include electrodes to provide current or voltage at a desired location within the patient's anatomical structure when powered and indicated by an external device (e.g., a patch or probe). In other embodiments, the electronic component may include a therapeutic agent that is released at a target location when powered by an external device.

[0080] The various embodiments described above may find particular relevance in high frequency ultrasound applications (e.g., frequencies of 20 MHz and above). For example, applications such as intravascular ultrasound (IVUS) imaging may benefit from these embodiments. In IVUS, the overall size of the transducer or transducer array may be limited to 1 mm or less in any given direction. When considering a device comprising a transducer array operating in the range of 20 MHz-60 MHz, the size of each array element will be from about 50 μm (micrometers) to about 10 μm. In these cases, even with micromachining techniques, the area of ​​the non-moving region of the CMUT structure effectively reduces the active area and may be severely limited. For example, for example, in conventional wafer bonding processes, 8 μm to 10 μm wide walls used to separate CMT membranes may significantly reduce the active area. The walls and pillars described herein help to increase (if not maximize) the transmit and receive performance of the device at the desired operating frequency. The disclosed embodiments help to improve the performance of the CMUT device while maintaining an acceptable yield and reliability of the resulting device.

[0081] The use of "suitable for" or "configured to" herein represents open and inclusive language, which does not exclude devices that are suitable for or configured to perform additional tasks or steps. In addition, the use of "based on" represents open and inclusive, because the process, step, calculation or other step "based on" one or more of the conditions or values ​​can be based on additional conditions or values ​​beyond the conditions in practice. The headings, lists and numbers included herein are only for convenience of explanation and are not meant to be limiting.

[0082] Although the present invention may allow for various modifications and alternative forms, specific embodiments have been shown by way of example in the accompanying drawings and have been described in detail herein. However, it should be understood that the present invention is not intended to be limited to the specific forms disclosed. On the contrary, the present invention includes all modifications, equivalents and substitutes that fall within the spirit and scope of the present invention as defined by the following appended claims.

Claims

1. A capacitive micromachined ultrasonic transducer (CMUT) device, comprising: substrate; one or more peripheral walls protruding from the base, the one or more peripheral walls defining an outer boundary of the cavity; a membrane bonded to the one or more peripheral walls, the cavity being located between the membrane and the substrate; one or more pillars protruding from the substrate, the one or more pillars being surrounded by the one or more peripheral walls, wherein at least a portion of the one or more pillars has a width of less than 10 microns; as well as One or more inner walls protrude from the base plate, the one or more inner walls being surrounded by the one or more peripheral walls.

2. The CMUT device according to claim 1, wherein: The one or more peripheral walls have a width of at least 8 microns.

3. The CMUT device according to claim 1, wherein: The membrane is not bonded to at least a portion of the one or more pillars.

4. The CMUT device according to claim 3, wherein: The membrane is not bonded to at least a portion of the one or more inner walls.

5. The CMUT device according to claim 4, wherein: The membrane is not bonded to any of the one or more pillars.

6. The CMUT device according to claim 1, wherein: The cavity comprises a negative gas pressure relative to an exterior of the CMUT device.

7. The CMUT device according to claim 1, wherein: The one or more pillars are at least 2 microns shorter than the one or more peripheral walls.

8. The CMUT device according to claim 1, wherein: The one or more pillars, wherein at least a portion of the one or more inner walls has a width of less than 1 micron.

9. A method for constructing a capacitive micromachined ultrasonic transducer (CMUT) device, comprising: Disposing one or more peripheral walls on the substrate, the one or more peripheral walls defining an outer boundary of the cavity, wherein the one or more peripheral walls have a width of at least 8 microns; Disposing one or more pillars on the substrate, the one or more pillars being surrounded by the one or more peripheral walls, wherein at least a portion of the one or more pillars has a width of 1 micrometer to 10 micrometers; and One or more inner walls protruding from the substrate are disposed on the substrate, the one or more inner walls being surrounded by the one or more peripheral walls, wherein a width of at least a portion of the one or more inner walls is 0.5 micrometers to 1 micrometer.

10. The method according to claim 9, further comprising: A membrane is bonded to the one or more peripheral walls, with the cavity being located between the membrane and the substrate.

11. The method according to claim 10, wherein: The membrane is bonded to the one or more peripheral walls while maintaining at least a portion of the one or more struts unbonded to the membrane.

12. The method according to claim 10, wherein: The membrane is not bonded to at least a portion of the one or more inner walls.

13. The method according to claim 10, wherein: The membrane is not bonded to any of the one or more pillars.

14. The method of claim 9, further comprising removing air from the cavity such that a negative air pressure is created within the cavity relative to an exterior of the CMUT device.

15. The method of claim 9, further comprising configuring the one or more pillars to be at least 2 nanometers shorter than the one or more peripheral walls.

16. A medical device comprising: ontology; At least one electronic component associated with the body, the at least one electronic component comprising: at least one sensor, and at least one ultrasonic transducer configured to receive ultrasonic signals and thereby power the at least one sensor, Wherein, the at least one electronic component is configured to provide a response ultrasonic wave in response to the determination of the at least one sensor.

17. The medical device according to claim 16, wherein: The at least one ultrasonic transducer comprises a capacitive micromachined ultrasonic transducer (CMUT).

18. The medical device according to claim 16, wherein: The at least one ultrasound transducer comprises a complementary metal oxide capacitive micromachined ultrasound transducer on silicon (CMUT-on-CMOS) device.

19. The medical device according to claim 18, wherein: The at least one sensor includes at least one of a pressure sensor and a flow sensor.

20. The medical device according to claim 18, wherein: The body includes a bracket.

21. A system comprising: an external device having a first ultrasonic transducer; A medical device configured to be positioned within an anatomical structure of a patient, the medical device comprising: at least one electronic component; at least one sensor, and a second ultrasonic transducer configured to receive the ultrasonic signal generated by the first ultrasonic transducer to power the at least one sensor, Wherein, the at least one electronic component is configured to provide a responsive ultrasonic wave to the external device in response to the determination of the at least one sensor.

22. The system of claim 21, wherein: At least one of the first ultrasonic transducer and the second ultrasonic transducer includes a capacitive micromachined ultrasonic transducer (CMUT).

23. The system of claim 22, wherein: At least one of the first ultrasonic transducer and the second ultrasonic transducer includes a complementary metal oxide capacitive micromachined ultrasonic transducer on silicon (CMUT-on-CMOS) device.

24. The system of claim 21, wherein: The at least one sensor includes at least one of a pressure sensor and a flow sensor.

25. The system of claim 21, wherein: The at least one sensor is configured to detect at least one of sugar level, pH level, CO2 level, oxygen level, pressure and temperature.

26. The system of claim 21, wherein: The at least one sensor is configured to detect moisture content of the tumor.

27. The system of claim 21, wherein: The at least one electronic component is coupled to the bracket.

28. The system of claim 21, wherein: The at least one electronic component is coupled to the aortic valve.

29. The system of claim 21, wherein: The external device includes a patch configured for adherence to the patient's skin.

30. The system of claim 21, wherein: The external device includes a handheld probe.

31. The system of claim 21, wherein: The external device includes a magnetic field generator.

32. The system of claim 21, wherein: The external device includes a power source, a processor, and a wireless communication device.

33. A method comprising: Implanting electronic components into a patient's body adjacent to or within a tumor; powering the electronic components using ultrasonic energy; detecting the moisture content of the tumor using a sensor of the electronic component; providing a response signal from the electronic component to an external device based on the detected moisture content; and Based on the response signal, the density or density change of the tumor is determined.

34. A medical device comprising: a flexible elongated member having a distal portion configured for insertion into a blood vessel of a patient; an imaging device disposed in the distal portion of the flexible elongated member, the imaging device comprising: Flexible substrates; a plurality of ultrasonic transducers disposed on the flexible substrate, each of the plurality of ultrasonic transducers comprising a complementary metal oxide capacitive micromachined ultrasonic transducer on silicon (CMUT-on-CMOS) device; and The tail portion extends from the flexible substrate and has a plurality of connection pads.

35. The medical device according to claim 34, wherein The plurality of ultrasonic transducers are arranged circumferentially around the longitudinal axis of the flexible elongated member.

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